In situ DNA probe hybridization assays will be used to determine the types of Human Papillomavirus (HPV) associated with oral cancers and other oral lesions. A panel of long, cloned DNA probes and a panel of short, synthetic DNA probes, specific for HPV Types 6, 11, 16, 18 & 31, will be tested on thin sections of tumor specimens from the archives of the Division of Oral Pathology, University of Washington. The specimens will include papiliomas and frank carcinomas. This study will demonstrate the feasibility of routine testing of oral biopsies for HPV infection by in situ hybridization, and may provide new information regarding the specific types of HPV associated with oral malignancy. In addition, this study will directly compare the efficacy of long, cloned DNA probes vs. short, synthetic DNA probes in in situ DNA hybridizations. The results of this project will be important for the commercial development of non-isotopic, DNA probe-based diagnostic systems for use in the Clinical and Oral Pathology Laboratories.